Incineration is a process used to burn waste substances in which all of the combustion factors, i.e. temperature, retention time, turbulence, and air supply, can be controlled. One of the basic requirements for incineration is therefore to maintain an air supply in the incinerator that is sufficient for waste destruction.
Due to an increase in environmental awareness and a decrease in available sites for land-fill operations, incineration systems are playing an increasing role in the field of waste management. The use of incineration systems is especially preferred in the disposal of various hazardous wastes. However, incineration of hazardous waste material inherently poses a serious threat to environmental concerns, and is therefore regulated by State and Federal agencies. These regulations require complete combustion of the hazardous waste in order to effect control of emissions released to the atmosphere. It is thus necessary that computer systems be developed which can closely monitor and control the waste destruction process to insure that complete combustion of the hazardous waste material has taken place, and which can respond rapidly to compensate for upsets that can occur in the combustion process.
Accordingly, it is a primary object of this invention to provide a method and apparatus for controlling the combustion air supplied to an incinerator that burns multiple waste fuels and where each waste fuel has a different theoretical air to fuel ratio. Another object of this invention is to control the combustion air so as to maintain a desired quantity of excess oxygen in the combustion gases of an incinerator that burns multiple waste fuels. It is a further object of this invention to provide the required quantity of air for complete combustion of hazardous waste material under regulations such as specified by the Federal Resources Conservation and Recovery Act (RCRA) for industrial waste disposal.